2 files changed, 18 insertions, 5 deletions

diff --git a/include/asm-ppc64/elf.h b/include/asm-ppc64/elf.h
index 8457d90244fb..6c42d61bedd1 100644
--- a/include/asm-ppc64/elf.h
+++ b/include/asm-ppc64/elf.h
@@ -229,9 +229,13 @@ do {								\
 
 /*
  * An executable for which elf_read_implies_exec() returns TRUE will
- * have the READ_IMPLIES_EXEC personality flag set automatically.
+ * have the READ_IMPLIES_EXEC personality flag set automatically. This
+ * is only required to work around bugs in old 32bit toolchains. Since
+ * the 64bit ABI has never had these issues dont enable the workaround
+ * even if we have an executable stack.
  */
-#define elf_read_implies_exec(ex, exec_stk)     (exec_stk != EXSTACK_DISABLE_X)
+#define elf_read_implies_exec(ex, exec_stk) (test_thread_flag(TIF_32BIT) ? \
+                (exec_stk != EXSTACK_DISABLE_X) : 0)
 
 #endif
 
diff --git a/include/asm-ppc64/page.h b/include/asm-ppc64/page.h
index 20e0f19324e8..86219574c1a5 100644
--- a/include/asm-ppc64/page.h
+++ b/include/asm-ppc64/page.h
@@ -252,10 +252,19 @@ extern u64 ppc64_pft_size;		/* Log 2 of page table size */
 
 /*
  * This is the default if a program doesn't have a PT_GNU_STACK
- * program header entry.
+ * program header entry. The PPC64 ELF ABI has a non executable stack
+ * stack by default, so in the absense of a PT_GNU_STACK program header
+ * we turn execute permission off.
  */
-#define VM_STACK_DEFAULT_FLAGS  (VM_READ | VM_WRITE | VM_EXEC | \
-                                 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
+#define VM_STACK_DEFAULT_FLAGS32        (VM_READ | VM_WRITE | VM_EXEC | \
+                                         VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
+
+#define VM_STACK_DEFAULT_FLAGS64        (VM_READ | VM_WRITE | \
+                                         VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
+
+#define VM_STACK_DEFAULT_FLAGS \
+        (test_thread_flag(TIF_32BIT) ? \
+         VM_STACK_DEFAULT_FLAGS32 : VM_STACK_DEFAULT_FLAGS64)
 
 #endif /* __KERNEL__ */
 #endif /* _PPC64_PAGE_H */